Preheat oven to 425 degrees F
Grease a 9 x 13 baking pan with non-stick spray.
In large skillet saute onions in butter until golden brown.
Whisk together eggs, and milk until smooth.
Stir in corn, bell pepper, muffin mix & dried oregano and mix well.
Grease 9x9 pan and pour mixture into small baking pan.
Bake for approximately 20 minutes or until golden brown.
Remove from oven and top with cheese.
Return to oven to melt & brown cheese for 5 minutes.